Structure of the Classification Number

The SuDocs Classification Number consists of a class stem and a suffix. The class stem is a general designation used to bring related publications together. The suffix uniquely identifies a publication and differentiates it from all others classified under the same stem.

The suffix consists of a book number, and sometimes additions to the book number. For numbered publications, the book number is usually derived from the numeric designation appearing on the publication. For unnumbered publications, the book number is usually derived from a word in the title using a Cutter number.

A fundamental rule in SuDocs classification is that each publication is assigned a unique classification number. In cases where an identical number would apply, a word, abbreviation, or number is added to the book number to differentiate the two. If a publication consists of multiple parts or issues, each discrete piece receives its own unique extension to the book number.

A Superintendent of Documents classification number begins with a capital letter or letters representing a Government department or agency; capital letters are used for all letters in Superintendent of Documents classification numbers:

A  (Department of Agriculture)

The letters are followed by a number representing the agency as a whole, or a subordinate office. This is followed by a period:

A 13. (Forest Service)

After the period, there is a number designating the series or serial title, or category of the publication, followed by a colon:

A 13.150:  (Southern Research Station: General Publications)

In this example, A 13.150: constitutes the class stem. The class stem alone shows that the publication in this example is a general publication issued by the Department of Agriculture, Southern Research Station.

The letters and numbers after the colon represent the individual publication:

In this example, W 64 is the book number.

Spacing is critical for the proper construction of the class number. A space must be inserted between letters and numbers in the class number unless there is intervening punctuation.

Formatting examples:

Incorrect SolutionCorrect formatting
A 93.2:AF8 Add a space between F and 8 A 93.2:AF 8
C 55.22/ 3:SE 1 Delete the space after the slash symbol C 55.22/3:SE 1
D5.317:616(717-5)A Add a space after D; before, after parentheses D 5.317:616 (717-5) A
D 101.11:9-2330-363-14 & P Remove spaces between 4&P D 101.11:9-2330-363-14&P
I 49.44/2: AS 3/4/2016 Delete the space after the colon I 49.44/2:AS 3/4/2016
  • Parentheses are the only exception to the spacing rule. One space must be inserted before and after a parenthesis, unless there is adjacent punctuation.
  • No spaces precede or follow symbols, such as the ampersand (&) or slash.
  • In classification numbers, roman numerals (I, II, III) should be converted to Arabic numerals (1, 2, 3).

Libraries can construct their own Superintendent of Documents classification numbers according to the principles outlined here. For documents falling in existing classes, find the class stem in the List of Classes. Add a Cutter number, date, or series number after the colon and an arbitrary designation such as “X” at the end to indicate that it is a locally assigned number.

Government publications are classified after they are received by LSCM; publications not received are not assigned classification numbers by LSCM.

Sorting in SuDocs Order

SuDocs classes are arranged alphabetically based on the leading letter(s). The number between the period and colon is a whole number (ex. HS 1.2: comes before HS 1.15:). After the colon, the hierarchy of sorting is as follows:


In both the class stem and the suffix, an empty space will file before a space that has a letter or number (i.e. ‘nothing’ before ‘something’). The ‘nothing’ aspect includes spaces and punctuation, with the exception of the colon. This is illustrated in the following list with the example of Y 4.EC 7:S.HRG.110-646 preceding Y 4.EC 7:SA 9/2.

Example of a SuDocs Sort

A 13.2:T 73/4
A 93.2:N 95/3
A 93.73:76
A 93.73:89
A 93.73/2:62
C 13.58:7564
C 13.58:7611
HE 20.4002:AD 9/2
HE 20.4002:AD 9/5
HE 20.4002:F 94
L 36.202:F 15/2
L 36.202:F 15/2/980
L 36.202:F 15/3
Y 1.1/7:109-118
Y 1.1/7:109-131
Y 1.1/7:110-6
Y 1.1/7:110-20
Y 4.EC 7:C 73/7
Y 4.EC 7:C 73/10
Y 4.EC 7:S.HRG.110-646
Y 4.EC 7:SA 9/2
Y 4.EC 7:SCH 6
Y 4.EC 7:SE 2

Superintendent of Documents Classification Guidelines

Introduction to the Classification Guidelines
The Classification System: A Brief History
Structure of the Classification Number
Sorting in SuDocs Order
Example of a SuDocs Sort
Class Stems
Letter Author Symbols
New Agency Classes
Joint Publications from Different Agencies
Publications Prepared by One Agency for Another
Serials with Changing Publishers
Joint Publications Issued in Series
Subordinate Offices
First and Second Levels
Assignment of Classes
Third and Fourth Levels
Joint Publications from Different Subagencies
Name Changes and Reorganizations
Category Classes
Most Frequently Used Category Classes
.1 - Annual reports
.2 - General publications
.8 - Handbooks, manuals, and guides
.11 - Maps and Charts
.12 - Posters
Less Frequent Category Classes
.3 - Bulletins
.4 - Circulars
.5 - Laws
.6 - Regulations, rules, and instructions
.7 - Press releases
.9 - Bibliographies and Lists of Publications
.10 - Directories
.13 - Forms
.14 - Addresses
Cutter Numbers
Cutter Table and Its Use
Filing Order for Cutter Numbers
Slash Numbers
Selecting Cutter Words
Words to Avoid when Cuttering
Sets With a Collective Title
Foreign Language Editions
Numbers in Titles
Cuttering Acronyms and Initialisms
Cuttering: Geographic Topics
Cuttering Related Documents Covering the Same Subject but Different
General Subjects and Geographic Terms
Cuttering Geographic Terms Using Personal Names
Cuttering Multi-Part Geographic Names
State Cutter Numbers
State Cutter Numbers Table
Additions to Book Numbers
Year Format
Dates for Revised Editions
Punctuation in Dates or Date Ranges
Volume, Part, Chapter, and Section Numbers
Volume Number and Date: Which Comes First?
Volume Number Followed by Date
Date Followed by Volume Number
Words and Abbreviations
Foreign-language Publications
Multiple Word Phrases in a Suffix
Multiple Versions of a Publication
Corrected Copies of Numbered Volumes
Standard Abbreviations and Words
State Abbreviations
Classes by Publication Type
Preliminary, Initial, Draft, and Final Reports
Preprints and Separates
Summaries and Executive Summaries
Electronic Products
Sets with Multiple Publication Types
Monographic Series
Identifying a Monographic Series
Assigning New Series Classes
Series Related to Existing Classes by Subject
Structure of the Series Class
Departmental Series vs. Bureau Series
Series Book Numbers
Series Numbering
Unusual Series Numbering
Series Numbering and Revised Editions
Numbering system changes
Two series on one publication
Series number vs. Agency control number
Letters and Phrases Appearing on Publications
Volumes, Parts, or Sections
Publications Which Are Not Serials or Series
Multipart Monographs versus Series
Other Situations
Continuing Resources
Identifying a Continuing Resource
Integrating Resources
Assigning New Continuing Resource Classes
Works Related to Category Classes
Works Related to Existing Classes by Subject
New Classes to Reflect Changes for Existing Serials
Serials within Series: Separate Class Approach
Serials with a Constant Series Number
Cuttering a Serial or, When Not to Establish a New Class Stem for a Serial
Serials within Series: Cuttering Approach
Publications of Short Duration
Other cases for Cuttering
Serials Designation
Number 1 for First Month Appears Annually
Date incorporated in Series Number
Volume and Number
Annual Publications
Semiannual Publications
Publications Issued Three or More Times a Year
Variations in Publication Cycles
Release Date vs. Coverage Date
Special Issues of Serials
Frequently Revised Monographs Cataloged as Serials
Presidential Publications
Presidential Committees and Commissions
Presidential Commissions vs Presidential Initiatives
Permanent Agencies Reporting to the President
Vice President of the United States
Congressional and Legislative Branch Publications
Y 4. - Congressional Committee Publications
Constructing the Committee Designation
Reorganized Committees and Name Changes
Y 4. Committee Print or Y 1. Report?
Joint Hearings
Publications Prepared by One Committee for the Use of Another
Individual Book Numbers
House Book Numbers
Numbered and Unnumbered Documents in One Class
Senate Book Numbers
Cutter Numbers
Multipart Works
Errors in Numbering on Publications
Y 1.-: - Congress as a Whole, House and Senate as a Whole
Individual Book Numbers
House and Senate Documents and Reports
Y 1.1/2: - U. S. Congressional Serial Set
Y 1.2/5: - United States Code
Boards, Commissions, and Independent or Temporary Committees Established by Congress
Boards, Commissions, and Committees Established within the Executive Branch
Executive Branch Independent Agencies with Limited Duration or Publishing Output
Y 3. - Boards, Commissions, and Independent or Temporary Committees
Agency Designations
Category and Series Designations
Related Series or Subjects
Individual Book Numbers
Y 3.2: - Limited Boards, Commissions, and Independent Committees
Y 4.2: and Y 4.3: - Select and Special Committees (As Appointed)
Y 7.1: - Memorial Addresses
Y 9. - Speeches
Y 10: and Y 11: - Subordinate Offices
X 1.1: - Congressional Record
XJH: and XJS: - House and Senate Journals
Y and X General Issues
Serial Publications
Star Prints
U.S. Participation in International Organizations
Cartographic Resources
Category Classes for Maps and Charts
General Rules
U.S. Geological Survey Maps
Map Reference Numbers
Northwest (NW) Quadrant
Northeast (NE) Quadrant
Southwest (SW) Quadrant
Southeast (SE) Quadrant
Edition Date
Bureau of Land Management Maps
U.S. Forest Service Maps
Revision Dates
National Ocean Service Nautical Charts
Map Types
Classification Guidelines for Digital Reproductions
Classification by Type of Digital Reproduction

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Please submit your questions about the Superintendent of Documents Classification Guidelines via askGPO by choosing the “Federal Depository Library Program” tile and selecting the category “Cataloging/Metadata (Policy and Records).